TODO

- [1.1.x] add :readonly option to :has_many.
- Work as framework on Rails.
- How to support dSCorePropagationData? ignore it?
  all systemOnly == "TRUE" attribute can be ignored?
- Add parsing position to DistinguishedNameInvalid error like
  <NAME=VALUE,INVALID_HERE>@<REST=INPUT>.
- Support TLS optioins (e.g. CA certification file and so on)
- Provide FormHelper for LDAP entry's attribute to handle multiple values
  (["foo", "bar", ...]) and option value ({"binary" => "..."},
  {"lang-en-us" => "..."})
- Test SASL bind.
- Add result pagination via LDAP::Controls
- serialize & serialized_attributes
- schema mgmt - how does AR handle it?
- columns() -- ?
http://api.rubyonrails.com/classes/ActiveRecord/Base.html#M000865
- provide full documentation for new API.
- handle all exception raised from Ruby/LDAP and wrap as
  ActiveLdap exception. I think we need to develop an
  application using ActiveLdap.
- Add locking around Timeout.alarm() to ensure a multithreaded ruby
  app doesn't hit any race conditions
- Add AR matching exceptions:
* ActiveRecordError -- ActiveLdapError as base
* AssociationTypeMismatch
* SerializationTypeMismatch
* ConnectionNotEstablished
* RecordNotFound
* LdapActionInvalid - like StatementInvalid
* MultiparameterAssignmentErrors
* AttributeAssignmentError
* RecordNotSaved